Comparative Analysis of Three Vertebral Screw Placement Directions in Anterior Thoracolumbar Fracture Surgery: A Finite Element Study

Abstract

Background: Thoracolumbar fractures, especially burst fractures, are common severe spinal injuries requiring surgery. The main goals are to restore spinal stability and normal curvature, relieve nerve compression, and prevent further neurological damage. Minimally invasive techniques are increasingly used in spinal surgery. This study aims to use finite element analysis to compare two new thoracolumbar anterior fixation systems: Hybrid cross-thoracolumbar fixation system and new hybrid cross-thoracolumbar fixation system (HXTL and NHXTL) with Medtronic's ANTERIOR system, providing a theoretical reference for surgeries.

Method: A finite element model of the T12–L2 vertebrae of a 27-year-old healthy male was built based on CT images. The model was processed, optimized, meshed, and analyzed using software. In vitro biomechanical tests were compared with the finite element model results to verify the model's validity. A 500 N compressive load and a 10 N m bending moment were applied to the upper surface of T12. The stress and displacement of the vertebral body and the stress state of the support body of the two models under various conditions like forward flexion and backward extension were observed and analyzed.

Results: The study compared the biomechanical performance of the HXTL, NHXTL, and ANTERIOR systems under six physiological conditions. The vertebral body displacement of the three systems was maximum under forward flexion. During right flexion, the HXTL displacement was significantly greater than that of the ANTERIOR and NHXTL systems, while during extension, the HXTL and NHXTL displacements were significantly less than those of the ANTERIOR system. Under other motion conditions, the displacements were relatively small. In terms of vertebral body stress, the ANTERIOR model had the maximum stress during left flexion, significantly greater than that of the other two. In terms of titanium mesh stress, the HXTL system had significantly higher stress during extension and left rotation compared to the other two systems. In terms of nail–rod stress, the ANTERIOR system had higher stress in all directions than the HXTL and NHXTL systems.

Conclusion: Compared with the ANTERIOR system, the HXTL system reduces the surgical incision through oblique nail placement, can reduce the risk of nail–rod failure, and increase the stability of the titanium mesh between vertebral bodies, but it also brings a higher risk of subsidence. The NHXTL model not only reduces the surgical incision and the risk of accidental injury to contralateral blood vessels but also reduces the risk of nail–rod failure and does not increase the risk of titanium mesh subsidence. It is a more optimized choice.

Keywords

anterior surgery / biomechanical comparison / finite element analysis / nail placement direction / thoracolumbar fractures

References

[1] K. B. Wood, W. Li, D. S. Lebl, and A. Ploumis, “Management of Thoracolumbar Spine Fractures,” Spine Journal 14 (2014): 145-164.

[2] M. Zileli, S. Sharif, and M. Fornari, “Incidence and Epidemiology of Thoracolumbar Spine Fractures: WFNS Spine Committee Recommendations,” Neurospine 18 (2021): 704-712.

[3] M. Muratore, S. Allasia, P. Viglierchio, et al., “Surgical Treatment of Traumatic Thoracolumbar Fractures: A Retrospective Review of 101 Cases,” Musculoskeletal Surgery 105 (2021): 49-59.

[4] S. Sharif, Y. Shaikh, O. Yaman, and M. Zileli, “Surgical Techniques for Thoracolumbar Spine Fractures: WFNS Spine Committee Recommendations,” Neurospine 18 (2021): 667-680.

[5] V. Parmar, E. Bond, P. S. Page, and D. T. Josiah, “Radiographic Outcomes Following Various Treatment Options of Thoracolumbar Burst Fractures,” International Journal of Spine Surgery 17 (2023): 174-178.

[6] L. Dai, “Principles of Management of Thoracolumbar Fractures,” Orthopaedic Surgery 4 (2012): 67-70.

[7] J. D. Burrington, “Anterior Approach to the Thoracolumbar Spine: Technical Considerations,” Archives of Surgery 111 (1976): 456.

[8] Q. Zhu, F. Shi, W. Cai, J. Bai, J. Fan, and H. Yang, “Comparison of Anterior Versus Posterior Approach in the Treatment of Thoracolumbar Fractures: A Systematic Review,” International Surgery 100 (2015): 1124-1133.

[9] G. J. Xu, Z. J. Li, J. X. Ma, T. Zhang, X. Fu, and X. L. Ma, “Anterior Versus Posterior Approach for Treatment of Thoracolumbar Burst Fractures: A Meta-Analysis,” European Spine Journal 22 (2013): 2176-2183.

[10] J. Allain, “Anterior Spine Surgery in Recent Thoracolumbar Fractures: An Update,” Orthopaedics and Traumatology, Surgery and Research 97 (2011): 541-554.

[11] P. Banczerowski, G. Czigléczki, Z. Papp, R. Veres, H. Z. Rappaport, and J. Vajda, “Minimally Invasive Spine Surgery: Systematic Review,” Neurosurgical Review 38 (2015): 11-26.

[12] I. Hussain, K.-M. Fu, J. S. Uribe, D. Chou, and P. V. Mummaneni, “State of the Art Advances in Minimally Invasive Surgery for Adult Spinal Deformity,” Spine Deformity 8 (2020): 1143-1158.

[13] G. A. Ricciardi, J. I. Cirillo Totera, J. P. Cabrera, A. Guiroy, C. A. Carazzo, and R. Yurac, “Minimally Invasive Surgery for Traumatic Thoracolumbar Fractures: A Cross-Sectional Study of Spine Surgeons,” World Neurosurgery 180 (2023): e706-e715.

[14] K.-M. Scheufler, “Technique and Clinical Results of Minimally Invasive Reconstruction and Stabilization of the Thoracic and Thoracolumbar Spine With Expandable Cages and Ventrolateral Plate Fixation,” Neurosurgery 61 (2007): 798-809.

[15] Y. Kikuchi, M. Shimada, S. Yamaguchi, and Y. Hara, “Finite Element Analysis Predictions in the Canine Lumbar Spine Are Useful and Correlate With Ex Vivo Biomechanical Studies,” American Journal of Veterinary Research 1-8 (2023): 1-8.

[16] S. Huang, C. Zhou, X. Zhang, et al., “Biomechanical Analysis of Sandwich Vertebrae in Osteoporotic Patients: Finite Element Analysis,” Frontiers in Endocrinology 14 (2023): 1259095.

[17] H. Guo, Y. Tang, D. Guo, et al., “Stability Evaluation of Oblique Lumbar Interbody Fusion Constructs With Various Fixation Options: A Finite Element Analysis Based on Three-Dimensional Scanning Models,” World Neurosurgery 138 (2020): e530-e538.

[18] K. K. Lee, E. C. Teo, F. K. Fuss, et al., “Finite-Element Analysis for Lumbar Interbody Fusion Under Axial Loading,” IEEE Transactions on Biomedical Engineering 51, no. 3 (2004): 393-400, https://doi.org/10.1109/TBME.2003.820994.

[19] S. Zahaf, S. Kebdani, A. Mestar, N. Zina, and B. Aour, “Biomechanical Evaluation of Two Posterior Lumbar Intervertebral Fusion Surgical Scenarios Reinforced by a Rigid Posterior Fixation System in the Vertebral Column Analyzed by the Finite Element Method,” Nano Biomedicine and Engineering 10 (2018): 258-278.

[20] S. Zahaf, B. Mansouri, A. Belarbi, et al., “The Effect of the Posterior Loading on the Spine of a School Child,” Advances in Cancer Prevention 1, no. 3 (2016): 1000112.

[21] T. Wang, Y. Zhao, Z. Cai, et al., “Effect of Osteoporosis on Internal Fixation After Spinal Osteotomy: A Finite Element Analysis,” Clinical Biomechanics 69 (2019): 178-183.

[22] J.-C. Li, T.-H. Xie, Z. Zhang, Z.-T. Song, Y.-M. Song, and J.-C. Zeng, “The Mismatch Between Bony Endplates and Grafted Bone Increases Screw Loosening Risk for OLIF Patients With ALSR Fixation Biomechanically,” Frontiers in Bioengineering and Biotechnology 10 (2022): 862951.

[23] K.-T. Kang, Y.-G. Koh, J. Son, J. S. Yeom, J.-H. Park, and H.-J. Kim, “Biomechanical Evaluation of Pedicle Screw Fixation System in Spinal Adjacent Levels Using Polyetheretherketone, Carbon-Fiber-Reinforced Polyetheretherketone, and Traditional Titanium as Rod Materials,” Composites Part B: Engineering 130 (2017): 248-256.

[24] G. S. Lewis, D. Mischler, H. Wee, J. S. Reid, and P. Varga, “Finite Element Analysis of Fracture Fixation,” Current Osteoporosis Reports 19 (2021): 403-416.

[25] Z. J. Tseng, J. L. Mcnitt-Gray, H. Flashner, X. Wang, and R. Enciso, “Model Sensitivity and Use of the Comparative Finite Element Method in Mammalian Jaw Mechanics: Mandible Performance in the Gray Wolf,” PLoS One 6 (2011): e19171.

[26] S. Zahaf and S. Kebdani, “Biomechanical Study Between the Rigid and Dynamic Fixation Systems of the Spinal Column Analyzed by the Finite Element Method,” Nano Biomedicine and Engineering 9 (2017): 169-183.

[27] Q. Zhang, T. Chon, Y. Zhang, J. S. Baker, and Y. Gu, “Finite Element Analysis of the Lumbar Spine in Adolescent Idiopathic Scoliosis Subjected to Different Loads,” Computers in Biology and Medicine 136 (2021): 104745.

[28] F. Somovilla-Gómez, R. Lostado-Lorza, M. Corral-Bobadilla, and R. Escribano-García, “Improvement in Determining the Risk of Damage to the Human Lumbar Functional Spinal Unit Considering Age, Height, Weight and Sex Using a Combination of FEM and RSM,” Biomechanics and Modeling in Mechanobiology 19 (2020): 351-387.

[29] F. Gómez, R. Lorza, M. Bobadilla, and R. García, “Improving the Process of Adjusting the Parameters of Finite Element Models of Healthy Human Intervertebral Discs by the Multi-Response Surface Method,” Materials 10 (2017): 1116.

[30] M. Song, K. Sun, Z. Li, et al., “Stress Distribution of Different Lumbar Posterior Pedicle Screw Insertion Techniques: A Combination Study of Finite Element Analysis and Biomechanical Test,” Scientific Reports 11 (2021): 12968.

[31] H. Schmidt, F. Heuer, U. Simon, et al., “Application of a New Calibration Method for a Three-Dimensional Finite Element Model of a Human Lumbar Annulus Fibrosus,” Clinical Biomechanics 21 (2006): 337-344.

[32] X. Chen, K. Nakamura, M. Mori, et al., “Finite Element Analysis for Large Deformation Frictional Contact Problems With Finite Sliding[J],” JSME International Journal Series A Solid Mechanics and Material Engineering 42, no. 2 (1999): 201-208.

[33] R. J. Gu, P. Murty, and Q. Zheng, “Use of Penalty Variable in Finite Element Analysis of Contacting Objects[J],” Computers and Structures 80 (2002): 2449-2459.

[34] N. J. Carpenter, R. L. Taylor, and M. G. Katona, “Lagrange Constraints for Transient Finite Element Surface Contact,” International Journal for Numerical Methods in Engineering 32 (1991): 103-128.

[35] B. Keddar, B. Aour, S. Zahaf, and C. Boualem, “Static Study and Finite Element Analysis of a New Method of Fixation of a Medial Humerus Fracture by an Intramedullary Nailing System Analyzed by the ANSYS Workbench 16.2 Calculus Code,” Nano Biomedicine and Engineering 11 (2019): 272-289.

[36] S. Zahaf, M. Dahmane, B. Azzeddine, I. Bouri, and N. Afane, “Failure Analysis of Semi-Elliptical Crack Behavior in the Cement Mantle of a Total Hip Prosthesis,” Materials Physics and Mechanics 48 (2022): 242-271.

[37] A. Mestar, S. Zahaf, N. Zina, and A. Boutaous, “Development and Validation of a Numerical Model for the Mechanical Behavior of Knee Prosthesis Analyzed by the Finite Elements Method,” Journal of Biomimetics, Biomaterials and Biomedical Engineering 37 (2018): 12-42.

[38] I. Keddar, B. Aour, and S. Zahaf, “Comparative Study of the Fractured Humerus Fixation by Intramedullary Nailing and Compression Plate,” Journal of Failure Analysis and Prevention 22 (2022): 1905-1923.

[39] B. Khuyagbaatar, K. Kim, and Y. H. Kim, “Recent Developments in Finite Element Analysis of the Lumbar Spine,” International Journal of Precision Engineering and Manufacturing 25, no. 2 (2023): 487-496.

[40] H. Lu, Q. Zhang, F. Ding, Q. Wu, and R. Liu, “Establishment and Validation of a T12-L2 3D Finite Element Model for Thoracolumbar Segments,” American Journal of Translational Research 14 (2022): 1606.

[41] M. M. Panjabi, M. Kifune, W. Liu, M. Arand, A. Vasavada, and T. R. Oxland, “Graded Thoracolumbar Spinal Injuries: Development of Multidirectional Instability,” European Spine Journal 7 (1998): 332-339.

[42] P. Korovessis, V. Syrimpeis, and A. Korovesis, “Is Open Anterior Advantageous to Posterior Decompression and Reconstruction in Fresh A₃ to C₃/AO Type Thoracolumbar Junction Fractures? A Systematic Review,” Expert Review of Medical Devices 21 (2024): 411-425.

[43] Y. Yao, J. Yan, F. Jiang, S. Zhang, and J. Qiu, “Comparison of Anterior and Posterior Decompressions in Treatment of Traumatic Thoracolumbar Spinal Fractures Complicated With Spinal Cord Injury,” Medical Science Monitor: International Medical Journal of Experimental and Clinical Research 26 (2020): e927284-1-e927284-7.

[44] P. A. Christiansen, S. Huang, J. S. Smith, M. E. Shaffrey, J. S. Uribe, and C.-P. Yen, “Mini-Open Lateral Retropleural/Retroperitoneal Approaches for Thoracic and Thoracolumbar Junction Anterior Column Pathologies,” Neurosurgical Focus 49 (2020): E13.

[45] R. J. Malik, M. H. Falahee, E. N. Kahn, M. J. Heidenreich, D. Springstead, and A. Aziz, “Rapid, Midline Retroperitoneal Exposure for Four-Level Anterior Lumbar Interbody Fusion—Technical Case Atlas,” Journal of Surgical Case Reports 2021 (2021): rjab351.

[46] R. W. Ikard, “Methods and Complications of Anterior Exposure of the Thoracic and Lumbar Spine,” Archives of Surgery 141 (2006): 1025.

[47] K. Jendoubi, Y. Khadri, M. Bendjaballah, and N. Slimane, “Effects of the Insertion Type and Depth on the Pedicle Screw Pullout Strength: A Finite Element Study,” Applied Bionics and Biomechanics 2018 (2018): 1-9.

[48] D. Nakashima, K. Ishii, Y. Nishiwaki, et al., “Quantitative CT-Based Bone Strength Parameters for the Prediction of Novel Spinal Implant Stability Using Resonance Frequency Analysis: A Cadaveric Study Involving Experimental Micro-CT and Clinical Multislice CT,” European Radiology Experimental 3 (2019): 1.

[49] B. B. Abshire, R. F. McLain, A. Valdevit, and H. E. Kambic, “Characteristics of Pullout Failure in Conical and Cylindrical Pedicle Screws After Full Insertion and Back-Out,” Spine Journal 1 (2001): 408-414.

[50] D. W. Kiner, C. D. Wybo, W. Sterba, Y. N. Yeni, S. W. Bartol, and R. Vaidya, “Biomechanical Analysis of Different Techniques in Revision Spinal Instrumentation: Larger Diameter Screws Versus Cement Augmentation,” Spine 33 (2008): 2618-2622.

[51] A. G. U. Brantley, J. K. Mayfield, J. B. Koeneman, and K. R. Clark, “The Effects of Pedicle Screw Fit: An: In Vitro: Study,” Spine 19 (1994): 1752.

[52] W. Sterba, D.-G. Kim, D. P. Fyhrie, Y. N. Yeni, and R. Vaidya, “Biomechanical Analysis of Differing Pedicle Screw Insertion Angles,” Clinical Biomechanics 22 (2007): 385-391.

[53] F. Amirouche, G. F. Solitro, and B. P. Magnan, “Stability and Spine Pedicle Screws Fixation Strength—A Comparative Study of Bone Density and Insertion Angle,” Spine Deformity 4 (2016): 261-267.

[54] J. C. Rodríguez-Olaverri, A. Hasharoni, H. DeWal, R. M. Nuzzo, F. J. Kummer, and T. J. Errico, “The Effect of End Screw Orientation on the Stability of Anterior Instrumentation in Cyclic Lateral Bending,” Spine Journal 5 (2005): 554-557.

[55] W. C. Horton, S. F. Blackstock, J. T. Norman, C. S. Hill, M. A. Feiertag, and W. C. Hutton, “Strength of Fixation of Anterior Vertebral Body Screws,” Spine 21 (1996): 439-444.

[56] C. P. DiPaola, J. A. Jacobson, H. Awad, B. P. Conrad, and G. R. Rechtine, “Screw Orientation and Plate Type (Variable- vs. Fixed-Angle) Effect Strength of Fixation for In Vitro Biomechanical Testing of the Synthes CSLP,” Spine Journal 8 (2008): 717-722.

[57] P. Ren, X. Cheng, C. Lu, et al., “Finite Element Analysis of a Novel Anterior Locking Plate for Thoracolumbar Burst Fracture,” BioMed Research International 2021 (2021): 1-9.

[58] A. Rohlmann, T. Zander, and G. Bergmann, “Comparison of the Biomechanical Effects of Posterior and Anterior Spine-Stabilizing Implants,” European Spine Journal 14 (2005): 445-453.

[59] M. Hussain, A. Nassr, R. N. Natarajan, H. S. An, and G. B. J. Andersson, “Biomechanical Effects of Anterior, Posterior, and Combined Anterior-Posterior Instrumentation Techniques on the Stability of a Multilevel Cervical Corpectomy Construct: A Finite Element Model Analysis,” Spine Journal 11 (2011): 324-330.

[60] K. Zhang, Y. Yang, L. Ma, et al., “Biomechanical Effects of a Novel Anatomic Titanium Mesh Cage for Single-Level Anterior Cervical Corpectomy and Fusion: A Finite Element Analysis,” Frontiers in Bioengineering and Biotechnology 10 (2022): 881979.

[61] Z. He, Y. Ou, B. Hou, J. Wei, and X. Mu, “A Meta-Analysis of the Safety and Effectiveness of Titanium Mesh Versus Bone Graft Alone for the Treatment of Thoracolumbar Tuberculosis,” European Spine Journal 29 (2020): 1505-1517.

[62] Y. Li, H. Wang, W. Cui, and C. Li, “Comparison of 3D Printed Cervical Spine With Titanium Mesh Cage for Fractures of Lower Cervical Spine,” Chinese Journal of Orthopaedic Trauma 12 (2018): 705-711.

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2025 The Author(s). Orthopaedic Surgery published by Tianjin Hospital and John Wiley & Sons Australia, Ltd.